1. Field of the Invention
The present disclosure relates to a hybrid type liquid crystal display device (or ‘LCD’). Especially, the present disclosure relates to a hybrid liquid crystal display device in which some portions represent external images disposed behind the liquid crystal panel so that this external image is shown with the images represented by the liquid crystal display device itself.
2. Discussion of the Related Art
As the features of the light weight, the thin panel, and the lower driving electric consumption, the application of the LCD is prevailed for various fields. For examples, the LCD is applied to the portable computer including notebook computers, the office automation devices, the audio/video system, or the outdoor/indoor commercial advertising devices. The transparent type liquid crystal display device, mostly used type, implements the video data by modulating the light incident from the back light unit.
FIG. 1 is an assembling perspective view illustrating the structure of the liquid crystal display device according to the related art. Referring to FIG. 1, the liquid crystal display device having the edge type back light unit comprises the liquid crystal display panel (or LCD panel) 12, and the edge back light unit disposed under the LCD panel 12.
The LCD panel 12 includes an upper substrate, a lower substrate, and a liquid crystal layer of any mode type between the two substrates. At the front and rear sides of the LCD panel 12, a first polarization film 21 and a second polarization film 23 are disposed, respectively.
The edge type back light unit comprises a light source 15, a light guide panel 16, and a plurality of optical sheets 14, and irradiates the back light to the LCD panel 12 by changing the light of the light source to a surface source light. The light source 15 supplies the light to at least one side surface of the light guide panel 16. The optical sheets 14 include one or more prism sheet and one or more diffusion sheet for diffusing the light from the light guide panel 16 and guiding the light to vertically enter into the light incident surface of the LCD panel 12. The optical sheets 14 may have the dual brightness enhancement film (or ‘DBEF’).
Under the light source 15 and the light guide panel 16, a reflective sheet 19 is disposed. The reflective sheet 19 reuses the light lost through the rear surface of the light guide panel 16 by reflecting it to the front side where the LCD panel 12 is disposed.
There is a cover bottom 17 under the light source 15, the light guide panel 16 and the reflective sheet 19. The cover bottom 17 includes the material high strength and high thermal conductivity for quickly radiating the heat from the light source 15 to external of the LCD device. Fore example, the cover bottom 17 may comprises a metallic coated plate such as aluminum, aluminum-nitride (AlN), Electrolytic Galvanized Iron (EGI), stainless steel, galvaume (SGLC), aluminum coated iron (ZnAl), and tin coated plate (SPTE). Furthermore, materials for enhancing the thermal conductivity can be coated on the cover bottom 17.
A guide panel 13 and a top case 11 are disposed by surrounding the LCD panel 12. The guide panel 13 is the rectangular molded frame made of the synthetic resin (such as polycarbonate) with the glass fiber, and wraps the upper circumferences and the sides of the LCD panel 12 and the sides of the back light unit. The guide panel 13 supports the LCD panel 12, and maintains the gap between the LCD panel 12 and the optical sheets 14 evenly. The top case 11 made of the metal materials like the cover bottom 17 surrounds the upper surface and the side surface of the guide panel 13, and is fixed with at least one of the guide panel 13 and the cover bottom 17 using hooks or screws.
The LCD is one of the display device for implementing video data by irradiating the light from the light source to the LCD panel disposed between two polarizing sheets of which polarizing axes are perpendicularly set, and by controlling the transmissivity of the polarized light using the polarizing property of the light and the anisopropic light refractive property of the liquid crystal material. Therefore, the LCD can passively display the video image on the display area of the display system according to the electric signals. In some cases for implementing complex video data, it is required for a hybrid display system in that the LCD image is combined with an additional image represented on an external screen disposed behind the LCD.
However, the LCD according to the related art is for showing the video data singly because it can not pass any external images through itself. Furthermore, there is no idea for LCD to implement complex images by combining or mixing the video images of the LCD with the external images.